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Juárez-Cortés MZ, Vázquez LEC, Díaz SFM, Cardona Félix CS. Streptococcus iniae in aquaculture: a review of pathogenesis, virulence, and antibiotic resistance. Int J Vet Sci Med 2024; 12:25-38. [PMID: 38751408 PMCID: PMC11095286 DOI: 10.1080/23144599.2024.2348408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Accepted: 04/18/2024] [Indexed: 05/18/2024] Open
Abstract
One of the main challenges in aquaculture is pathogenic bacterial control. Streptococcus iniae stands out for its ability to cause high mortality rates in populations of commercially important fish populations and its recent recognition as an emerging zoonotic pathogen. The rise in identifying over 80 strains some displaying antibiotic resistance coupled with the emerging occurrence of infections in marine mammal species and wild fish underscores the urgent need of understanding pathogenesis, virulence and drug resistance mechanisms of this bacterium. This understanding is crucial to ensure effective control strategies. In this context, the present review conducts a bibliometric analysis to examine research trends related to S. iniae, extending into the mechanisms of infection, virulence, drug resistance and control strategies, whose relevance is highlighted on vaccines and probiotics to strengthen the host immune system. Despite the advances in this field, the need for developing more efficient identification methods is evident, since they constitute the basis for accurate diagnosis and treatment.
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Affiliation(s)
| | - Luz Edith Casados Vázquez
- CONAHCYT- Universidad de Guanajuato. Food Department, Life Science Division, University of Guanajuato Campus Irapuato-Salamanca. Irapuato, Guanajuato, México
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Kayansamruaj P, Dinh-Hung N, Srisapoome P, Na-Nakorn U, Chatchaiphan S. Genomics-driven prophylactic measures to increase streptococcosis resistance in tilapia. JOURNAL OF FISH DISEASES 2023; 46:597-610. [PMID: 36708284 DOI: 10.1111/jfd.13763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 05/07/2023]
Abstract
Streptococcosis caused by Streptococcus agalactiae and S. iniae is a significant problem that affects the success of tilapia aquaculture industries worldwide. In this critical review, we summarize the applicable practical strategies which may effectively enhance the world tilapia aquaculture development. Recently, the effect of vaccination and selective breeding programmes has been recognized as valuable tools to control the target disease and other consequent negative impacts caused by chemical and drug application. Advances in sequencing and molecular technologies are vital helpful factors with which to develop robust vaccines and increase the selective breeding programme's precision against streptococcosis. The genomic selection for streptococcosis-resistant tilapia strains and crucial genomic application for genomics' contribution to the development of novel Streptococcus vaccine, comparative genomics approach identifying vaccine candidates by reverse vaccinology, and next-generation vaccine design were described. Information from our review is encouraging for practical implementation of the development of vaccination and genomic selection in tilapia for streptococcosis resistance, which may be vital factors to sustain the world tilapia aquaculture industry effectively.
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Affiliation(s)
- Pattanapon Kayansamruaj
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
- Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
| | - Nguyen Dinh-Hung
- Center of Excellence in Fish Infectious Diseases (CE FID), Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Prapansak Srisapoome
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
- Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
| | - Uthairat Na-Nakorn
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
- Academy of Science, The Royal Society of Thailand, Bangkok, Thailand
| | - Satid Chatchaiphan
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, Thailand
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Pirollo T, Perolo A, Mantegari S, Barbieri I, Scali F, Alborali GL, Salogni C. Mortality in farmed European eel (Anguilla anguilla) in Italy due to Streptococcus iniae. Acta Vet Scand 2023; 65:5. [PMID: 36788544 PMCID: PMC9926715 DOI: 10.1186/s13028-023-00669-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 02/01/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND Streptococcal infections are one of the main causes of fish disease. During the last decade, Streptococcus iniae has become one of the most important aquatic pathogens worldwide, causing high losses in marine and freshwater finfish. Clinical signs in farmed fish include loss of appetite, lethargy and grouping at the bottom of the tank. Gross changes comprise darkening of the skin and haemorrhage at the basis of fins and opercula. To date, S. iniae has been isolated from several wild and farmed fish species but never in the European eel (Anguilla anguilla). In Europe, eel production from aquaculture is around 4500 tonnes and Italy is the third largest producer. This communication represents the first report of an outbreak of S. iniae infection in European eels. CASE PRESENTATION The outbreak occurred at an eel farm in northern Italy between May 2021 and September 2021. The outbreak caused about 2% mortality per month, resulting in the loss of about 10% of the farmed fish. The diseased eels showed apathy, lethargy, inactivity and inappetence. In July 2021, three eels were necropsied. Necropsy revealed skin and branchial hyperaemia, a few skin ulcers, and diffuse peritoneal congestion with a few haemorrhagic-like spot lesions. Swab samples for bacteriology were taken from the kidneys, liver, spleen, and brain. Additionally, four eels were opened and swap samples as above were taken. All the investigated eels were found dead. Bacteriological examination revealed growth of Streptococcus spp. from all samples. Identification of S. iniae was done by biochemical characterization, the API20STREP microsystem, 16S rDNA sequencing, and MALDI-TOF. Antimicrobial therapy (oxytetracycline and erythromycin) was ineffective. CONCLUSIONS This is the first report of S. iniae infection in the European eel. Although this may be an isolated outbreak, it is of concern due to the losses associated with this pathogen in fish worldwide and because the European eel is an endangered species. Due to the difficulties of controlling the disease with antimicrobials, it is advisable to plan other effective control measures, such as improving water quality and the environmental conditions, reducing fish density, improving biosecurity, and by using immunostimulants and, when possible, vaccines.
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Affiliation(s)
- Teresa Pirollo
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna “Bruno Ubertini”, Via Antonio Bianchi 7/9, 25124 Brescia, Italy
| | - Alberto Perolo
- A. I. A. - Agricola Italiana Alimentare S.p.A, Via Valpantena 18/G, 37142 Verona, Italy
| | - Simone Mantegari
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna “Bruno Ubertini”, Via Antonio Bianchi 7/9, 25124 Brescia, Italy
| | - Ilaria Barbieri
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna “Bruno Ubertini”, Via Antonio Bianchi 7/9, 25124 Brescia, Italy
| | - Federico Scali
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna "Bruno Ubertini", Via Antonio Bianchi 7/9, 25124, Brescia, Italy.
| | - Giovanni Loris Alborali
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna “Bruno Ubertini”, Via Antonio Bianchi 7/9, 25124 Brescia, Italy
| | - Cristian Salogni
- Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna “Bruno Ubertini”, Via Antonio Bianchi 7/9, 25124 Brescia, Italy
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Nguyen DT, Marancik D, Soto E. B-glucan immunostilulation against columnaris in a white sturgeon (Acipenser transmontanus) model. FISH AND SHELLFISH IMMUNOLOGY REPORTS 2022; 3:100067. [DOI: 10.1016/j.fsirep.2022.100067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/11/2022] [Accepted: 08/22/2022] [Indexed: 11/17/2022] Open
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Mugetti D, Colussi S, Pastorino P, Varello K, Tomasoni M, Menconi V, Pedron C, Bozzetta E, Acutis PL, Prearo M. Episode of mortality associated with isolation of Streptococcus iniae in Adriatic sturgeon (Acipenser naccarii Bonaparte, 1836) reared in Northern Italy. JOURNAL OF FISH DISEASES 2022; 45:939-942. [PMID: 35263448 DOI: 10.1111/jfd.13608] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Affiliation(s)
- Davide Mugetti
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Silvia Colussi
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Paolo Pastorino
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Katia Varello
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Mattia Tomasoni
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Vasco Menconi
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | | | - Elena Bozzetta
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Pier Luigi Acutis
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
| | - Marino Prearo
- Istituto Zooprofilattico Sperimentale of Piemonte, Liguria and Valle d'Aosta, Torino, Italy
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Xiao Z, Li X, Xue M, Zhang M, Liu W, Fan Y, Chen X, Chu Z, Gong F, Zeng L, Zhou Y. Vibrio metschnikovii, a Potential Pathogen in Freshwater-Cultured Hybrid Sturgeon. Animals (Basel) 2022; 12:ani12091101. [PMID: 35565528 PMCID: PMC9101323 DOI: 10.3390/ani12091101] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 02/01/2023] Open
Abstract
Simple Summary In an era of shrinking stocks and intensive fisheries production, pathogenic microorganisms are a serious threat to fish health. This study confirms that Vibrio metschnikovii—a pathogen mainly found in aquatic environments—was the pathogenic bacterium causing disease in hybrid sturgeon. The authors reveal the hazard of V. metschnikovii to hybrid sturgeon and the potential risks to the sturgeon farming industry. Abstract In July 2021, a disease with a high mortality rate broke out in freshwater cultured hybrid sturgeon in Zhengzhou, Henan Province. A dominant strain, H-701, was isolated from diseased fish; physiological changes in diseased fish were investigated and molecular identification, biochemical characterization, and pathogenicity and drug sensitivity tests of H-701 were performed. The 16S rRNA gene sequence of H-701 was 99.86% homologous with that of Vibrio metschnikovii in GenBank. The 50% lethal dose of H-701 was 3.72 ± 0.929 × 104 CFU/g fish weight. The proportion of monocytes, neutrophils, and eosinophils in the blood of diseased sturgeon increased significantly, whereas the proportion of lymphocytes decreased. In diseased fish, the serum levels of total protein, albumin, globulin, and alkaline phosphatase decreased significantly, and those of aspartate aminotransferase, alanine aminotransferase, and complement C3 increased significantly. There were obvious pathological changes in several tissues of the diseased fish. H-701 was sensitive to antibiotics such as florfenicol, enrofloxacin, and doxycycline. This study not only demonstrated that V. metschnikovii was the cause of death of a large number of hybrid sturgeon but also revealed its potential risk in hybrid sturgeon aquaculture. The results provide a basis for the diagnosis and prevention of this disease.
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Affiliation(s)
- Zidong Xiao
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Xudong Li
- Henan Fishery Technical Extension Station, Zhengzhou 450008, China;
| | - Mingyang Xue
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
| | - Mengwei Zhang
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
- Department of Aquatic Animal Medicine, College of Fisheries, Huazhong Agricultural University, Wuhan 430070, China
| | - Wei Liu
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
| | - Yuding Fan
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
| | - Xihua Chen
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
| | - Zhipeng Chu
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
| | - Feilong Gong
- Zhengzhou Fishery Technical Extension Station, Zhengzhou 450006, China;
| | - Lingbing Zeng
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
| | - Yong Zhou
- Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China; (Z.X.); (M.X.); (M.Z.); (W.L.); (Y.F.); (X.C.); (Z.C.); (L.Z.)
- Correspondence:
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Colussi S, Pastorino P, Mugetti D, Antuofermo E, Sciuto S, Esposito G, Polinas M, Tomasoni M, Burrai GP, Fernández-Garayzábal JF, Acutis PL, Pedron C, Prearo M. Isolation and Genetic Characterization of Streptococcus iniae Virulence Factors in Adriatic Sturgeon ( Acipenser naccarii). Microorganisms 2022; 10:883. [PMID: 35630328 PMCID: PMC9144172 DOI: 10.3390/microorganisms10050883] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023] Open
Abstract
The first case of infection of Streptococcus iniae in Adriatic sturgeon (Acipenser naccarii) was recently reported in a raceway system located in Northern Italy. A second episode of infection in sturgeons with absence of mortality and evident clinical signs, was registered in November 2020 in the same farm and is reported in this study. Histopathological changes observed in infected organs are described. The strains isolated in the two episodes were compared using molecular analysis based on PCR, phylogeny and virulence factors analysis. Not all the major virulence factors were detected for the two strains; in particular the strains 78697, isolated in November, lacks cpsD, compared to the strains 64844, isolated in September. Moreover, genetic variations were reported for lctO and pmg genes. These findings let us hypothesize a different virulence of the strains in accordance with clinical findings related to the sturgeons.
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Affiliation(s)
- Silvia Colussi
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Paolo Pastorino
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Davide Mugetti
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Elisabetta Antuofermo
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy; (E.A.); (M.P.); (G.P.B.)
| | - Simona Sciuto
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Giuseppe Esposito
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Marta Polinas
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy; (E.A.); (M.P.); (G.P.B.)
| | - Mattia Tomasoni
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Giovanni Pietro Burrai
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy; (E.A.); (M.P.); (G.P.B.)
| | | | - Pier Luigi Acutis
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | | | - Marino Prearo
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
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Miller EA, Leidholt S, Galvin T, Norton A, Van Houtan KS, Vega Thurber R, Boustany A. Electron microscopy reveals viral-like particles and mitochondrial degradation in scombrid puffy snout syndrome. DISEASES OF AQUATIC ORGANISMS 2021; 147:25-31. [PMID: 34789585 DOI: 10.3354/dao03634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aquaculture is an increasingly important food resource, but its sustainability is often limited by disease. In Scombridae fishes, puffy snout syndrome (PSS) is a debilitating condition where tumor-like collagenous growths form around the eyes, nares, and mandibles which impair vision and feeding and frequently lead to mortality. While PSS is considered an infectious or metabolic disease, no disease agents or promoters have been identified. Here, we used electron microscopy (EM) to describe the cellular pathology and search for etiological agents of PSS in Pacific mackerel Scomber japonicus, the first use of this approach for PSS. We examined aquaculture specimens across a range of apparent PSS severity, comparing the results to both wild and aquaculture asymptomatic mackerel. EM imagery consistently revealed viral-like particles in PSS samples, as well as the uniform absence of bacteria, protists, fungi, and other multicellular parasites. In addition to viral-like particles, symptomatic fish had a higher mean percentage of swollen and disintegrating mitochondria than both asymptomatic aquaculture and wild mackerel. This suggests that degraded mitochondria may be related to PSS and could be important to further understanding the origin, promoters, and prevention of PSS. This study serves as a first step in identifying the etiological agents of PSS.
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Affiliation(s)
- Emily A Miller
- Monterey Bay Aquarium, 886 Cannery Row, Monterey, CA 93940, USA
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Nguyen DT, Marancik D, Ware C, Griffin MJ, Soto E. Mycobacterium salmoniphilum and M. chelonae in Captive Populations of Chinook Salmon. JOURNAL OF AQUATIC ANIMAL HEALTH 2021; 33:107-115. [PMID: 33780059 DOI: 10.1002/aah.10124] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 01/20/2021] [Indexed: 06/12/2023]
Abstract
Chinook Salmon Oncorhynchus tshawytscha is a keystone fish species in the Pacific Northwest. In 2019, unusual mortalities occurred in two different populations of cultured fingerlings from the same facility in California, USA. The systems consist of outdoor, enclosed, flow-through freshwater tanks that are maintained at 18 ± 1°C. Clinical signs and gross findings were only observed in one population and included abnormal swimming, inappetence, lethargy, skin discoloration, and the presence of multifocal nodular and ulcerative skin lesions. Microscopic lesions were infrequent and consisted of severe, locally extensive granulomatous dermatitis and myositis and mild, multifocal, granulomatous branchitis, myocarditis, and hepatitis. Intracellular acid-fast organisms were observed within areas of granulomatous myositis. Posterior kidney swabs were collected and inoculated in nutrient-rich and selective agar media and incubated at 25°C for 2 weeks. Visibly pure bacterial colonies were observed 7-10 d postinoculation. Partial sequences of 16S rRNA initially identified the recovered bacteria as members of the genus Mycobacterium. However, marked variability was observed among Mycobacterium spp. isolates by using repetitive extragenic palindromic polymerase chain reaction fingerprinting. Amplification and sequencing of the ribosomal RNA internal transcribed spacer, 65-kDa heat shock protein, and RNA polymerase β-subunit gene of the cultured isolates identified M. salmoniphilum and M. chelonae, discrete members of the M. chelonae-abscessus complex, isolated from diseased Chinook Salmon fingerlings.
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Affiliation(s)
- Diem Thu Nguyen
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, 2108 Tupper Hall, Davis, California, 95616-5270, USA
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, True Blue, Grenada, West Indies
| | - David Marancik
- Department of Pathobiology, School of Veterinary Medicine, St. George's University, True Blue, Grenada, West Indies
| | - Cynthia Ware
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, 127 Experiment Station Road, Post Office Box 197, Stoneville, Mississippi, 38776, USA
| | - Matt J Griffin
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, 127 Experiment Station Road, Post Office Box 197, Stoneville, Mississippi, 38776, USA
| | - Esteban Soto
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, 2108 Tupper Hall, Davis, California, 95616-5270, USA
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Multifactorial Causes of Chronic Mortality in Juvenile Sturgeon ( Huso huso). Animals (Basel) 2020; 10:ani10101866. [PMID: 33066257 PMCID: PMC7602020 DOI: 10.3390/ani10101866] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 01/05/2023] Open
Abstract
This investigation focused on an episode of chronic mortality observed in juvenile Huso huso sturgeons. The examined subjects underwent pathological, microbiological, molecular, and chemical investigations. Grossly severe body shape deformities, epaxial muscle softening, and multifocal ulcerative dermatitis were the main observed findings. The more constant histopathologic findings were moderate to severe rarefaction and disorganization of the lymphohematopoietic lymphoid tissues, myofiber degeneration, atrophy and interstitial edema of skeletal epaxial muscles, and degeneration and atrophy of the gangliar neurons close to the myofibers. Chemical investigations showed a lower selenium concentration in affected animals, suggesting nutritional myopathy. Other manifestations were nephrocalcinosis and splenic vessel wall hyalinosis. Septicemia due to bacteria such as Aeromonas veronii, Shewanella putrefaciens, Citrobacter freundii, Chryseobacterium sp., and pigmented hyphae were found. No major sturgeon viral pathogens were detected by classical methods. Next-generation sequencing (NGS) analysis confirmed the absence of viral pathogens, with the exception of herpesvirus, at the order level; also, the presence of Aeromonas veronii and Shewanella putrefaciens was confirmed at the family level by the metagenomic classification of NGS data. In the absence of a primary yet undetected biological cause, it is supposed that environmental stressors, including nutritional imbalances, may have led to immune system impairment, facilitating the entry of opportunistic bacteria and mycotic hyphae.
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Heckman TI, Griffin MJ, Camus AC, LaFrentz BR, Morick D, Smirnov R, Ofek T, Soto E. Multilocus sequence analysis of diverse Streptococcus iniae isolates indicates an underlying genetic basis for phenotypic heterogeneity. DISEASES OF AQUATIC ORGANISMS 2020; 141:53-69. [PMID: 32940251 DOI: 10.3354/dao03521] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Streptococcus iniae is a Gram-positive, opportunistically zoonotic bacterium infective to a wide variety of farmed and wild fish species worldwide. Outbreaks in wild fish can have detrimental environmental and cultural impacts, and mortality events in aquaculture can result in significant economic losses. As an emerging or re-emerging pathogen of global significance, understanding the coalescing factors contributing to piscine streptococcosis is crucial for developing strategies to control infections. Intraspecific antigenic and genetic variability of S. iniae has made development of autogenous vaccines a challenge, particularly where the diversity of locally endemic S. iniae strains is unknown. This study genetically and phenotypically characterized 11 S. iniae isolates from diseased wild and farmed fish from North America, Central America, and the Caribbean. A multilocus sequence analysis (MLSA) scheme was developed to phylogenetically compare these isolates to 84 other strains of Streptococcus spp. relevant to aquaculture. MLSA generated phylogenies comparable to established genotyping methods, and isolates formed distinct clades related to phenotype and host species. The endothelial Oreochromis mossambicus bulbus arteriosus cell line and whole blood from rainbow trout Oncorhynchus mykiss, Nile tilapia Oreochromis niloticus, and white sturgeon Acipenser transmontanus were used to investigate the persistence and virulence of the 11 isolates using in vitro assays. In vivo challenges using an O. niloticus model were used to evaluate virulence by the intragastric route of infection. Isolates showed significant differences (p < 0.05) in virulence and persistence, with some correlation to genogroup, establishing a basis for further work uncovering genetic factors leading to increased pathogenicity.
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Affiliation(s)
- Taylor I Heckman
- Aquatic Animal Health Laboratory, Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Nguyen DT, Marancik D, Soto E. Intracoelomic- and Intramuscular-Injection Challenge Model of Piscine Streptococcosis in White Sturgeon Fingerlings. JOURNAL OF AQUATIC ANIMAL HEALTH 2020; 32:133-138. [PMID: 32845532 DOI: 10.1002/aah.10112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/24/2020] [Accepted: 07/05/2020] [Indexed: 06/11/2023]
Abstract
Streptococcus iniae is a zoonotic pathogen and one of the major aetiologic agents of streptococcosis. In White Sturgeon Acipenser transmontanus, S. iniae infection typically presents as a necrotizing and heterophilic myositis, causing 30-50% mortality in infected fish. To gain a better understanding of the pathogenesis of streptococcosis in White Sturgeon, and to identify the experimental route of infection that most closely mimics the natural disease, fingerlings were challenged with a single dose of 1.3 × 108 cells/fish of S. iniae that was administered via intracoelomic/intraperitoneal (IC) or intramuscular (IM) routes. Acute mortalities were present only in the IM-challenged fish, with first mortality occurring 4 d postchallenge and the mortality rate reaching 18.3% after 9 d. The challenged fish presented erratic swimming, ulcerative skin lesions, and hemorrhages in the liver and swim bladder. Streptococcus iniae was recovered from the kidney and brain tissues of moribund and dead fish. Histopathologic analysis of fish that died acutely revealed massive proliferation of bacteria in the muscle at the injection site and within vascular organs such as the heart and spleen, with variable amounts of tissue necrosis including a necrotizing myositis. Fish that died closer to 9 d postchallenge demonstrated more pronounced multifocal to locally extensive granulomatous inflammation of skeletal muscle at the injection site, liver, kidney, and spleen. No mortality, clinical signs, or gross changes were observed in the control or IC-challenged fish. Postmortem evaluation of 10 survivors in each treatment was performed to determine carrier status in the brain and posterior kidney tissues. The prevalence of S. iniae in survivors was 10% and 0% in the IM- and IC-challenged groups, respectively. The results from this study suggest that IM-injection challenge methods are suitable for inducing streptococcosis in White Sturgeon, and they may be the preferred method for studying the pathogenesis of the naturally occurring disease in this species.
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Affiliation(s)
- Diem Thu Nguyen
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, California, 95616, USA
- Department of Pathobiology, St. George's University School of Veterinary Medicine, Grenada
| | - David Marancik
- Department of Pathobiology, St. George's University School of Veterinary Medicine, Grenada
| | - Esteban Soto
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, California, 95616, USA
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